From 5df87c1556515dfae504da342990821f407a8c99 Mon Sep 17 00:00:00 2001 From: Richard Kuo Date: Mon, 31 Oct 2011 18:52:00 -0500 Subject: [PATCH] Hexagon: Implement basic TLB management routines for Hexagon. Mostly all stubs, as the TLB is managed by the hypervisor. Signed-off-by: Richard Kuo Acked-by: Arnd Bergmann Signed-off-by: Linus Torvalds --- arch/hexagon/include/asm/tlb.h | 39 ++++++++++++ arch/hexagon/include/asm/tlbflush.h | 58 ++++++++++++++++++ arch/hexagon/mm/vm_tlb.c | 93 +++++++++++++++++++++++++++++ 3 files changed, 190 insertions(+) create mode 100644 arch/hexagon/include/asm/tlb.h create mode 100644 arch/hexagon/include/asm/tlbflush.h create mode 100644 arch/hexagon/mm/vm_tlb.c diff --git a/arch/hexagon/include/asm/tlb.h b/arch/hexagon/include/asm/tlb.h new file mode 100644 index 000000000000..473abde01d62 --- /dev/null +++ b/arch/hexagon/include/asm/tlb.h @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#ifndef _ASM_TLB_H +#define _ASM_TLB_H + +#include +#include + +/* + * We don't need any special per-pte or per-vma handling... + */ +#define tlb_start_vma(tlb, vma) do { } while (0) +#define tlb_end_vma(tlb, vma) do { } while (0) +#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0) + +/* + * .. because we flush the whole mm when it fills up + */ +#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm) + +#include + +#endif diff --git a/arch/hexagon/include/asm/tlbflush.h b/arch/hexagon/include/asm/tlbflush.h new file mode 100644 index 000000000000..b89a90251225 --- /dev/null +++ b/arch/hexagon/include/asm/tlbflush.h @@ -0,0 +1,58 @@ +/* + * TLB flush support for Hexagon + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#ifndef _ASM_TLBFLUSH_H +#define _ASM_TLBFLUSH_H + +#include +#include + +/* + * TLB flushing -- in "SMP", these routines get defined to be the + * ones from smp.c, else they are some local flavors. + */ + +/* + * These functions are commonly macros, but in the interests of + * VM vs. native implementation and code size, we simply declare + * the function prototypes here. + */ +extern void tlb_flush_all(void); +extern void flush_tlb_mm(struct mm_struct *mm); +extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr); +extern void flush_tlb_range(struct vm_area_struct *vma, + unsigned long start, unsigned long end); +extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); +extern void flush_tlb_one(unsigned long); + +/* + * "This is called in munmap when we have freed up some page-table pages. + * We don't need to do anything here..." + * + * The VM kernel doesn't walk page tables, and they are passed to the VMM + * by logical address. There doesn't seem to be any possibility that they + * could be referenced by the VM kernel based on a stale mapping, since + * they would only be located by consulting the mm structure, and they + * will have been purged from that structure by the munmap. Seems like + * a noop on HVM as well. + */ +#define flush_tlb_pgtables(mm, start, end) + +#endif diff --git a/arch/hexagon/mm/vm_tlb.c b/arch/hexagon/mm/vm_tlb.c new file mode 100644 index 000000000000..c6ff41575461 --- /dev/null +++ b/arch/hexagon/mm/vm_tlb.c @@ -0,0 +1,93 @@ +/* + * Hexagon Virtual Machine TLB functions + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/* + * The Hexagon Virtual Machine conceals the real workings of + * the TLB, but there are one or two functions that need to + * be instantiated for it, differently from a native build. + */ +#include +#include +#include + +/* + * Initial VM implementation has only one map active at a time, with + * TLB purgings on changes. So either we're nuking the current map, + * or it's a no-op. This operation is messy on true SMPs where other + * processors must be induced to flush the copies in their local TLBs, + * but Hexagon thread-based virtual processors share the same MMU. + */ +void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + + if (mm->context.ptbase == current->active_mm->context.ptbase) + __vmclrmap((void *)start, end - start); +} + +/* + * Flush a page from the kernel virtual map - used by highmem + */ +void flush_tlb_one(unsigned long vaddr) +{ + __vmclrmap((void *)vaddr, PAGE_SIZE); +} + +/* + * Flush all TLBs across all CPUs, virtual or real. + * A single Hexagon core has 6 thread contexts but + * only one TLB. + */ +void tlb_flush_all(void) +{ + /* should probably use that fixaddr end or whateve label */ + __vmclrmap(0, 0xffff0000); +} + +/* + * Flush TLB entries associated with a given mm_struct mapping. + */ +void flush_tlb_mm(struct mm_struct *mm) +{ + /* Current Virtual Machine has only one map active at a time */ + if (current->active_mm->context.ptbase == mm->context.ptbase) + tlb_flush_all(); +} + +/* + * Flush TLB state associated with a page of a vma. + */ +void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr) +{ + struct mm_struct *mm = vma->vm_mm; + + if (mm->context.ptbase == current->active_mm->context.ptbase) + __vmclrmap((void *)vaddr, PAGE_SIZE); +} + +/* + * Flush TLB entries associated with a kernel address range. + * Like flush range, but without the check on the vma->vm_mm. + */ +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + __vmclrmap((void *)start, end - start); +} -- 2.20.1